GLANDERS AND FARCY 35 



on boiled potato, also on the sterilized serum of the horse and sheep, and 

 produced glanders in horses and other animals by inoculation with the 

 pure cultures. 



Infection of Glanders. Communication of glanders from one horse 

 to another with which it may be in contact is a fact which is hardly 

 questioned in the present day, but it is also true that in many cases a 

 glandered horse has been kept in a stable with a number of others without 

 any extension of the disease so far as an ordinary clinical examination 

 would enable an observer to determine. This circumstance has been noted 

 by some of the older writers. On the other hand, recent investigations 

 prove that the period of incubation, by which term is meant the period 

 which elapses between the introduction of the virus and the declaration 

 of the disease, 'is exceedingly variable, although it has been stated by 

 different writers that it may extend from a few days to a year. 



Incubation. Experiments go to prove that an inoculated ass, an 

 animal which is very susceptible to glanders, will be visibly affected in the 

 course of six or seven days. It is, of course, almost impossible to determine 

 the exact date of infection under ordinary circumstances, and there is also 

 to be taken into account the question of susceptibility; but altogether 

 the evidence which has been obtained by very careful enquiry leads to 

 the conclusion that when the infective material is introduced into a horse's 

 system through the breathing organs, or an open wound in any part of 

 the body, the disease in some stage will be developed in the course of 

 a few days. It may, however, remain in an absolutely dormant condition 

 for months or years, and during this time, although the animal is to all 

 intents and purposes a glandered horse, there may not be any external 

 evidence whatever of the existence of the disease. It is consequently 

 easy to understand authorities having expressed various opinions in refer- 

 ence to the incubative period. 



Symptoms of Glanders. Since the introduction of the mallein test 

 it is not of so much importance as it formerly was to estimate the value of 

 certain indications which were once looked upon as sufficient to render an 

 animal suspected. The distinctive symptoms of the worst stage of glanders 

 are not easily mistaken; in fact, they are quite familiar to most persons 

 who have been in any way concerned with the management of horses. 

 Ulceration of the lining membrane of the nostrils, with an adhesive dis- 

 charge at first of semi-transparent character and later of a purulent nature, 

 with swelling of the glands under the jaw, are among the most character- 

 istic symptoms. The local disease of the nasal membrane is commonly 

 confined to one side, so far at least as clinical examination can determine, 

 and the enlarged glands are always on the side corresponding to the 



